https://github.com/torvalds/linux
Revision 2aa958c99c7fd3162b089a1a56a34a0cdb778de1 authored by Kairui Song on 18 January 2019, 11:13:08 UTC, committed by Borislav Petkov on 01 February 2019, 17:18:54 UTC
Kexec-ing a kernel with "efi=noruntime" on the first kernel's command
line causes the following null pointer dereference:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
  #PF error: [normal kernel read fault]
  Call Trace:
   efi_runtime_map_copy+0x28/0x30
   bzImage64_load+0x688/0x872
   arch_kexec_kernel_image_load+0x6d/0x70
   kimage_file_alloc_init+0x13e/0x220
   __x64_sys_kexec_file_load+0x144/0x290
   do_syscall_64+0x55/0x1a0
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

Just skip the EFI info setup if EFI runtime services are not enabled.

 [ bp: Massage commit message. ]

Suggested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: bhe@redhat.com
Cc: David Howells <dhowells@redhat.com>
Cc: erik.schmauss@intel.com
Cc: fanc.fnst@cn.fujitsu.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: kexec@lists.infradead.org
Cc: lenb@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: Philipp Rudo <prudo@linux.vnet.ibm.com>
Cc: rafael.j.wysocki@intel.com
Cc: robert.moore@intel.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: Yannik Sembritzki <yannik@sembritzki.me>
Link: https://lkml.kernel.org/r/20190118111310.29589-2-kasong@redhat.com
1 parent 912139c
Raw File
Tip revision: 2aa958c99c7fd3162b089a1a56a34a0cdb778de1 authored by Kairui Song on 18 January 2019, 11:13:08 UTC
x86/kexec: Don't setup EFI info if EFI runtime is not enabled
Tip revision: 2aa958c
README
Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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